1. Field of the Invention
The present invention relates generally to a wind turbine and more specifically it relates to a wind turbine system for safe and reliable installation in a building.
2. Description of the Related Art
Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.
Small wind turbine systems, which are generally defined as 100 kilowatts in capacity or lower, are designed to be installed at homes, farms and small businesses either as a source of backup electricity or to offset use of utility power and reduce electricity bills. A small wind turbine system rated in the range of 5-10 kilowatts would be required to provide a significant contribution for an average American home, which consumes approximately 10,000 kilowatt-hours of electricity per year. However, small wind turbine systems are currently primarily being used in rural homes and farms due to the large space required for tower installation (property size of half acre or more is desirable), while residential and business sectors have been more inclined to pursue solar power options for alternative energy needs.
Conventional ground based wind turbine systems typically include towers which generally fall into one of two categories: self-supporting (free standing) or guyed. A self-supporting tower has a large base, is constructed of larger scaffolding, and requires a large and expensive concrete foundation. A guyed tower is typically supported by guy wires, which tend to be obstructive and occupy large space.
Recently efforts have been made to address the space limitation of conventional ground based wind turbine systems by mounting a wind turbine on the rooftop or edge of a building. However, several problems have become apparent through use of such rooftop installations of wind turbine systems. Vibrations from the turbine may be transferred to the building structure, which can lead to noise and structural problems with the building. Further, when the turbine is installed on a rooftop or attached to a building, the roof base or building wall bearing the weight of the wind turbine system is much weaker compared to a ground base. This problem can create significant risks when the wind turbine system is subjected to extreme weather conditions such as a strong wind force. The weight of the wind turbine system also limits the capacity of a rooftop installation based system, in that the wind turbine itself must be limited to a specific weight (typically micro turbines are used with a capacity equal to or less than 1 kilowatt). Finally, wind turbulence on rooftops may cause problems with the normal operation of the system and significantly reduce the life of the turbine. Wind turbulence causes excessive wear and tear to the wind turbine and turbulent air flow can result in low efficiency in terms of converting energy to electricity as the constantly changing wind direction causes the wind turbine rotor to chase the wind rather than generating electricity from the wind. To minimize this impact; the rotor of the wind turbine must be positioned well above the roof line, which may not always be possible given the weak support from the building roof structure.
Because of the inherent problems with the related art, there is a need for a new and improved wind turbine system that does not suffer from the drawbacks associated with conventional ground based installations and rooftop installations of wind turbine systems.